I have owned multiples (many multiples) of both platforms, and I can tell you that I have not observed any reliability difference between the two.
I have too, and I havent been as lucky with the 1911's. Of all the 1911's (30+) I've owned, better than a third of the were problematical, and required work out of the box, or soon had issues down the road. Most of these were non Colt guns purchased in the late 90's, early 2000's.
The most reliable were the Colts or GI guns, and a few early Springfields, back when they still made them to, or closer to the original specs. The worst were the later Springfields. Of the 8 or so of their guns I've owned, the first two I bought back in the mid 80's were the only ones that worked without issue. Even then, I still had to do something to the guns to get them to the point I could use them, but that was more of a preference thing, sights, T&P, etc.
These days, I wouldnt trust any of the 1911's, other than the Colts, until I shot them, and these days, I'm even a little leery of Colt.
The SIG's on the other hand (17 to date), have required nothing, other than replacement night sights on a couple of used guns, and a couple of main springs on a couple of P6's to correct a heavier than necessary DA trigger. Other than that, load the mags and shoot, and right out of the box when new.
The size difference is huge when carrying everyday.
I suppose some are overly sensitive when it comes to size and weight.
I have both, and have carried both, and never noticed a bit of difference. The biggest difference between the two, is about a half inch in barrel length. I've also carried 1911 Government Models and Commanders, and again, no difference.
With the SIG's, you will really see no difference in size between their full and "compact" size guns, until you get into the P230/232, or the new P238. The others are all pretty much the same size, with at most, a half inch here or there being the difference.